Originally Posted by
wineberserkers
...also, Avios.com is not available to those outside the UK
It officially requires a UK address, yes. That is because it is a mass-market shopping scheme in the UK, with primarily UK only based partners.
Keep in mind you only need the Avios.com go-between if your BAEC account is in a BA Household account grouping. If just an individual BA Exec Club account on its own then IB+ account <> BAEC account direct transfers are fine.